The Fabulous Baker Boys (1989) is a charming mixture of film noir and
romantic comedy.

Jack and Frank make up a cocktail-lounge piano duet. They have been at it
for 15 years. The club where they work tells them that their act is old.
Jack, who is clearly frustrated by their life, talks Frank, who is satisfied
with their life, that they need a female singer. They interview candidates
and eventually find a punkish girl, Susie, who does not hike her dark past
(she is a call girl) has the right style of singing.
The first night she is nervous and stumbles on stage, but her voice soon
captures the audience. The "brothers" have a future again.
Except that Susie soon becomes the real attraction of the show.
Frank is openly jealous of Jack's attentions for Susie, and shows no respect
for the street girl.
The relationship between the two partners is somewhat morbid.
On tour, they sleep in the same bed. Frank keeps pictures of them, and
is clearly in love with their past: the duo is his life.
He is the "wife" of the couple.
Jack, on the other hand, is the frustrated husband of the couple, tired of
their habits (he used to be a brilliant jazz pianist).
She slowly replaces the "wife" of the couple. Jack is growing more and more
tired of their routine, of Frank's annoying (old) composure and his motherly
attention, and finds comfort in
Susie's casual and rebellious (young) attitude.
When Frank has to go out of town, and Susie has to perform alone with Jack,
she gives her sexiest performance on stage ever (dressed
in a red dress, unfulrling and moaning on Jack's piano), and becomes
Jack's sexual partner too. BUt Jack treats her coldly, and doesn't even react
when she tells him that she's thinking of leaving the act (just not glamorous
enough). He coolly replies that they would find another girl (which also
implies he could find another girl also as a sexual partner).
When Frank comes back from his trip, the rivalry between Frank and Susie
explodes: Susie challenges his leadership (Frank has always been making
the business decisions) and tries to talk Jack out of his slavery.
Jack feels that Susie is right, but is not ready to accept that she is
telling him the truth: that he has been prostituting his talent for years,
and Frank has been, de facto, his pimp. Instead, Jack ditches Susie, scorning
her affection/attention and calling her a whore. Susie calls him a loser.
He resentfully tells her that the duo has survived for 15 years and they
don't need her to save them (which is obviously false). She leaves.
Jack's loyalty/love for Frank prevails over the vision of a freer life with Susie.
But the crisis is only postponed. Frank books them a commercial with a small
tv station. The station treats them like amateurs, Jack overreacts, they
get kicked out. Jack accuses Frank of having lost his dignity.
Frank admits the miserable state of their affairs, loses his temper and
attacks him. Jack loses his mind and breaks his old partner's fingers.
His sense of failure has led him to alienate the two people who really like
him. An orphan who takes care of his dog redeems him.
Frank is his life, and doesn't deserve to be treated like an enemy.
Susie was right about everything, and doesn't deserve to be treated like
a self-serving bitch. He makes peace with both (and only at this point
it is clear that Jack is the protagonist of the film) and she may give him
another chance after all.